Wasn't it The Old Man who wrote:

I've thrown together a layer control checkbox. It's not quite as fancy
as the one on maps.google.com.

    http://econym.org.uk/gmap/example_layercontrol.htm

I've not written a tut for it yet.

The bit that maps.google.com does, but I can't work out how to do is the
mouseout handling.

I've made my control rectangular, rather than the "tabbed" shape used by
maps.google.com so I don't have to worry about doing mouseovers and
mouseouts of non-rectangular objects, but I still can't get the mouseout
to do what I want.

I get a container mouseout event when the mouse goes over a checkbox, so
if I close the thing on container mouseout, the checkbox goes away just
as you try to click it. What I ended up doing was setting a timeout so
that the control goes away 5 seconds after you open it, which isn't
quite as pretty, but it does the job.

A side effect of having a rectangular container is that things get a bit
ugly if you use longer text for your checkbox labels. You'd need to make
the MoreControl and LayerControl wide enough for your longer text to
make it look nice again.

--
http://econym.org.uk/gmap
The Blackpool Community Church Javascript Team